Learn about some of the historic telescopes of Leiden, and the interesting discoveries they have led to.

The Old Observatory Leiden is the oldest working university observatory in the world. For over a
century it acted as a hub of innovative astronomical research, attracting world-renowned
scientists to use its telescopes and look up at the night sky to explore the unknown. These
telescopes are rich in history, and offer a glimpse into astronomy before the time of computers
and satellites.
For a limited time only, a pop-up expo of historical telescopes and astronomical instrumentation
provided by Rijksmusuem Boerhaave is being hosted by the Old Observatory, brought here by
Werkgroep Leidse Sterrewacht. This expo includes a lens viewer that Frederik Kaiser used to
see Halley's Comet from his attic in Leiden in 1835, of which he wrote his famous paper about.
To celebrate the Leiden 2022 day ‘Kiek’, the Old Observatory will offer its exclusive tours for
FREE. This tour will bring you to one of our historical telescopes and past the pop-up expo,
guided by one of our explainers who actively studies astronomy.
Please note that an entrance ticket to the Hortus Botanicus is required to visit the Old
Observatory.
Tours alternate between English and Dutch. See tour schedule below:
● 11:30 - 12:30 (walk-in from 11:15) (NL)
● 13:00 - 14:00 (walk-in from 12:45) (NL)
● 14:30 - 15:30 (walk-in from 14:15) (ENG)
● 4:00 PM - 5:00 PM (walk-in from 3:45 PM) (ENG)

For more information on how to book a tour and arrival information, please click here.

There is a limit of 15 people per tour