The Old Observatory of Leiden is the oldest university observatory in the world. Built in 1860 by the Dutch astronomer Frederik Kaiser, rather than take a streamlined approach in its construction, the architects chose to model it after a Russian palace.
What resulted was a stunning edifice housing four antique telescopes, the oldest including a wooden specimen dating back to 1838. All four telescopes remain in working order to this day, and are occasionally brought out upon request for demonstrations.
Nearby
About the source: Atlas Obscura
Atlas Obscura aims 'to inspire wonder and curiosity about the incredible world we all share'. You can contribute to their collection on their website.