Pip -l, 45 bytes

Z:R{sXtRAb:Ab%4\,c"XXXOOoo..."@b}MRaC KXL.CXD

Takes input as a command-line argument. Attempt This Online!

Explanation

High-level:

  R{sXtRAb:Ab%4\,c"XXXOOoo..."@b}              Apply this function
                                 MR            to each match
                                    C KXL.CXD  of this regex
                                   a           in the input string
Z:                                             Transpose the result
                                               Autoprint as lines (-l flag)

The regex:

   XL       Lowercase letter            [a-z]
  K         Apply Kleene star           [a-z]*
C           Wrap in a capturing group   ([a-z]*)
       XD   Digit                       \d
      C     Wrap in a capturing group   (\d)
     .      Concatenate                 ([a-z]*)(\d)

The replacement function takes three arguments: a is the full match, b is the first capturing group (a letter or empty string), c is the second capturing group (a digit).

R{sXtRAb:Ab%4\,c"XXXOOoo..."@b}
  s                              Space character
   Xt                            repeated 10 times
         Ab                      ASCII code of the letter (nil if empty string)
           %4                    Mod 4 ("a"->1, "b"->2, "c"->3, ""->nil)
             \,c                 Inclusive range from that number to the digit
                                 (treats a left argument of nil as 0)
       b:                        Assign that value to b
     RA                          and replace those indices in the space string
                "XXXOOoo..."@b   with the equivalent indices in this string
R                                Reverse to put the "top" of the building at the left

APL, 59 bytes ^SBCS

{⊖⍉↑(-N)↑¨(L/⍨1,2≤/L←A⍸⍵)↓¨(N←⎕D⍳⍵~A←'abc')↑¨⊂'XXXOOoo...'}

Try it on online!

Shorter than the other APL answers so far! I think it can probably be further golfed. Will add explanation soon!

Thanks to dzaima & hyper-neutrino for their advice in the The APL Orchard!

Jelly, 33 bytes

~kµṪV‘R×ØaiⱮ0xƲ)Ṗz0Ṛị“XXXOOoo... 

Try it online!

Full program returning a list of lines. If that isn't acceptable, +2 bytes.

Note the trailing space. Included my favourite:

.                 .
..               ..
...             ...
oooo           oooo
ooooo         ooooo
OOOOOO       OOOOOO
OOOOOOO     OOOOOOO
XXXXXXXX   XXXXXXXX
XXXXXXXXX XXXXXXXXX
XXXXXXXXXXXXXXXXXXX

How it works

~kµṪV‘R×ØaiⱮ0xƲ)Ṗz0Ṛị“XXXOOoo...  - Main link. Takes a string on the left
~                                 - Bitwise NOT. This maps digits d to ~d and non-digits to 0
 k                                - Partition the string after falsey values
                                     This groups the string as we want, with a trailing []
  µ            )                  - Over each element, either [L, x] or [x]:
   Ṫ                              -   Extract x, modifying the element
    V                             -   Evaluate as a digit
     ‘                            -   Increment
      R                           -   Create a range
              Ʋ                   -   Last 4 links as a monad f([L]) or f([]):
        ØaiⱮ                      -     Index in the alphabet
            0x                    -     Get that many zeros
                                       If the element was [x], this yields []
                                       If the element was [L, x], this returns 1, 2 or 3 zeros, depending on L
       ×                          -   Multiple elementwise, zeroing the first 1,2 or 3 elements in the range if L is in the element
                Ṗ                 - Remove the trailing [] element
                 z0               - Transpose, padding with zeros
                   Ṛ              - Reverse
                    ị“XXXOOoo...  - Index into "XXXOOoo... "

APL (Dyalog Extended), 67 bytes

{⊖⍉↑(((' '⍴⍨2⊃⊢),'XXXOOoo...'↑⍨1+⊃)∘⌽0,48|⎕UCS)¨'[abc]?\d'⎕S'\0'⊢⍵}

Try it online!

Longer than the other answer, but I'll try golfing it later. Proper explanation coming soon.

• '[abc]?\d'⎕S'\0'⊢⍵ - Extract single digits or characters followed by digits
• (((' '⍴⍨2⊃⊢),'XXXOOoo...'↑⍨1+⊃)∘⌽0,48|⎕UCS)¨ - Train to turn each digit or pair into a horizontal string
• ⊖⍉↑ - Turn it into a matrix, transpose to make it vertical, and flip it upside-down.

Japt -R, 36 bytes

óȦnãÒXÌ î"XXXOOoo..."hSpXÎnD)s9Ãz3

Try it

óȦnãÒXÌ î"..."hSpXÎnD)s9Ãz3     :Implicit input of string
ó                                 :Partition at
 È                                :Characters that return true when passed through the following function
  ¦                               :  Test for inequality with
   n                              :  Convert to number
    Ã                             :End function
     £                            :Map each X
      Ò                           :  Bitwise increment
       XÌ                         :  Last character of X
          î                       :  Slice the following to that length
           "..."                  :    Literal string
                h                 :    Replace as many characters as necessary at the start of that string with
                 S                :      Space
                  p               :      Repeat
                   XÎ             :        First character of X
                     n            :        Convert from base
                      D           :        14
                       )          :      End repeat
                        s9        :      Slice off the first 9 characters
                          Ã       :End map
                           z3     :Rotate clockwise by 90 degrees 3 times
                                  :Implicit output, joined by newlines

PHP, 131 114 bytes

for($b=10;$b--;print"
")foreach(str_split($argn)as$a)$c=strpos(' abc',$a)?:!print$a<$b|$b<$c?' ':'XXXOOoo...'[$b];

Try it online!

$ echo 2479742|php -nF land.php 
   . 
   . 
  ... 
  ooo 
  ooo 
 OOOOO 
 OOOOO 
XXXXXXX 
XXXXXXX 
XXXXXXX 


$ echo 011a2b3b5c9c9b5b3a2110|php -nF land.php 
      .. 
      .. 
      .. 
      oo 
     oooo 
     OOOO 
    OOOOOO 
   XXX  XXX 
 XXX      XXX 
XXX        XXX 


$ echo a2a0a0a4a0a06a0a0a4a0a0a2a0a0a4a0a06a0a0a4a0a0a2|php -nF land.php 



      o           o 
      o           o 
   O  O  O     O  O  O 
   O  O  O     O  O  O 
X  X  X  X  X  X  X  X  X 
X  X  X  X  X  X  X  X  X 
      X           X

05AB1E (legacy), 34 bytes

Rvy.ïi"XXXOOoo..."y>£ëðAykÝǝ])ζRí»

Uses the legacy version of 05AB1E to save 2 bytes, since ζ also works on strings instead of just lists of characters.

Try it online.

Explanation:

R                  # Reverse the (implicit) input-string
 v                 # Loop `y` over each character:
  y.ïi             #  If `y` is a digit:
      "XXXOOoo..." #   Push string "XXXOOoo..."
        y>£        #   And only leave the first `y`+1 characters as substring
     ë             #  Else (`y` is a letter):
       Ayk         #   Get the index of `y` in the lowercase alphabet
          Ý        #   Create a list in the range [0, alphabet-index]
      ð    ǝ       #   Replace in the string at the top of the stack the characters at
                   #   those indices with a space
 ]                 # Close the if-else statement and loop
  )                # Wrap all strings on the stack into a list
   ζ               # Zip/transpose; swapping rows/columns
    Rí             # Reverse this list, as well as each individual line
      »            # And join the strings by newlines
                   # (after which the result is output implicitly)

As for my favorite 'building', let's go with this tree. ;)

b2b3b4b5b6b7898b7b6b5b4b3b2

       .       
      ...      
     .....     
    ooooooo    
   ooooooooo   
  OOOOOOOOOOO  
 OOOOOOOOOOOOO 
XXXXXXXXXXXXXXX
      XXX      
      XXX      
 

Canvas, 35 33 bytes

±｛⌐╷≡？┤╵“`Fc|C！‟ｍ］ｃ96－ ×１１╋╋｝｝）⤢⇵

Try it here!

Perl 6, 93 bytes

{for 9...0 ->\n {say .subst(/(\D)?(.)/,{'XXXOOoo... '.comb[$1>=n>=ord($0//0)-96??n!!10]}):g}}

A block that takes in the string and prints to stdout.

Try it online!

PowerShell, 127 bytes

$r=,''*10
$args|% t*y|%{if($_-in97..99){$b=$_-96}else{,' '*$b+'XXXOOoo...'[$b.."$_"]+,' '*(9-"$_")|%{$r[--$i]+=$_}
$b=$i=0}}
$r

Try it online!

C, 130 126 chars

Kinda long compared to the competition, but I blame the language...

char*p,b[99];r=10,q;main(o){for(gets(&b);r--;puts(""))
for(p=b;q=*p++;)o=q<60?putchar("XXXOOoo... "[o<r&r<q-47?r:10]),-1:q-97;}

I don't know about favourite building, but one of the more recognizable ones around here is Globen, so here is a poor rendition of it.

% ./a.out <<<24556667777776665542


       ......       
    oooooooooooo    
  oooooooooooooooo  
 OOOOOOOOOOOOOOOOOO 
 OOOOOOOOOOOOOOOOOO 
XXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXX

C64 BASIC, 276 PETSCII chars

My own solution, golfed down to 276 chars and 10 lines of BASIC V2.0!

0inputa$:dIc$(10):fOi=0to9:rE c$(i):nE:fOr=0to9
1z=1
2c=aS(mI(a$,z,z+1))
3ifc>57tHgO8
4ifc>=57-r tH?c$(9-r);:gO6
5?" ";
6z=z+1:ifz<=len(a$)gO2
7?:nE:eN
8z=z+1:w=aS(mI(a$,z,z+1)):ifw>=57-r aNc<=73-r tH?c$(9-r);:gO6
9?" ";:gO6:dA"x","x","x","o","o","W","W",".",".","."

(copy and paste in an emulator to see the result).

And finally, my favourite monument, the Brooklyn Bridge :)

Python 2.7 - 186

Probably can be shorter...

x=[]
l=iter(raw_input())
a="XXX00oo..."
for i in l:
 try:i=int(i);o=0
 except:o=" abc".index(i);i=int(next(l))
 x.append(" "*o+a[o:i+1]+" "*(9-i))
for i in zip(*x)[::-1]:print''.join(i)

Sample run:

08040233245542332040800000247974200000011a2b3b5c9c9b5b3a2110
                             .              ..
 .                  .        .              ..
 .                  .       ...             ..
 o                  o       ooo             oo
 o        oo        o       ooo            oooo
 0 0     0000     0 0      00000           0000
 0 0  00 0000 00  0 0      00000          000000
 X X XXXXXXXXXXXX X X     XXXXXXX        XXX  XXX
 X X XXXXXXXXXXXX X X     XXXXXXX      XXX      XXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX        XXX

Sydney Harbour Bridge

a1a13443a1a2a3a4a5a6a6a7a7a8a8a8a8a9a9a9a9a9a9a8a8a8a8a7a7a6a6a5a4a4a3a2a13443a1a1
                   ......
               ..............
             ..................
           oooooooooooooooooooooo
          oooooooooooooooooooooooo
   00    000000000000000000000000000    00
  0000  00000000000000000000000000000  0000
  XXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
  XXXX                                 XXXX

Golden gate bridge / Cisco logo

a2a0a0a4a0a06a0a0a4a0a0a2a0a0a4a0a06a0a0a4a0a0a2



      o           o
      o           o
   0  0  0     0  0  0
   0  0  0     0  0  0
X  X  X  X  X  X  X  X  X
X  X  X  X  X  X  X  X  X
      X           X

Great question by the way!

Ruby, 88 85

Fun challenge!

9.downto(0){|h|puts$*[0].gsub(/(\D?)(.)/){'XXXOOoo... '[h<$1.hex-9||$2.hex<h ?-1:h]}}

Takes input on the commandline, eg:

ruby landscapes.rb 011a2b3b5c9c9b5b3a2110

Will print out:

      ..      
      ..      
      ..      
      oo      
     oooo     
     OOOO     
    OOOOOO    
   XXX  XXX   
 XXX      XXX 
XXX        XXX

GolfScript, 69

'XXXOOoo...':s\{.96>{96-.' '*\@>+}{47-<' '10*+10<s\}if}%10/zip-1%n*\;

Not far off the APL solution.

Test online

APL (69 66)

' XXXOOoo...'[1+⌽⍉⌽↑{z×(z<' abc'⍳⍵)<(1+⍎⍺)≥z←⍳10}/↑2↑¨I⊂⍨⎕D∊⍨I←⌽⍞]

Examples:

      ' XXXOOoo...'[1+⌽⍉⌽↑{z×(z<' abc'⍳⍵)<(1+⍎⍺)≥z←⍳10}/↑2↑¨I⊂⍨⎕D∊⍨I←⌽⍞]
0804023324554233204080

 .                  . 
 .                  . 
 o                  o 
 o        oo        o 
 O O     OOOO     O O 
 O O  OO OOOO OO  O O 
 X X XXXXXXXXXXXX X X 
 X X XXXXXXXXXXXX X X 
XXXXXXXXXXXXXXXXXXXXXX

      ' XXXOOoo...'[1+⌽⍉⌽↑{z×(z<' abc'⍳⍵)<(1+⍎⍺)≥z←⍳10}/↑2↑¨I⊂⍨⎕D∊⍨I←⌽⍞]
011a2b3b5c9c9b5b3a2110
      ..      
      ..      
      ..      
      oo      
     oooo     
     OOOO     
    OOOOOO    
   XXX  XXX   
 XXX      XXX 
XXX        XXX