4 rezonance
(Published today, 12:45 by gwai77)
Normal sudoku rules apply.

The numbers placed outside the main grid, indicate the number of visible buildings.
Sudokupad
Solution code: column 4 from top to bottom
Solved by jalebc, marcmees, Carolin, L00ping007, Siebuhh, cornuto, buzzard, SKORP17, mattnburris, RadchenkoAleksandr, bhambells, HeyItsErin, thomamas, Fisherman