observatory (n.)

• beacon
• belvedere
• bleachers
• bridge
• coelostat
• gallery
• gazebo
• grandstand
• lighthouse
• lookout
• loophole
• orrery
• outlook
• overlook
• peephole
• pharos
• planetarium
• reflector
• ringside
• spectrograph
• spectroscope
• telescope
• tower
• watchtower