# main building of the Old Observatory, Leiden, Netherlands: what it is and when to go

> main building of the Old Observatory, Leiden is a university building and observatory in Leiden (Oude Sterrewacht (hoofdgebouw)) in Netherlands (Alphen aan den Rijn). Interests: History and Stargazing. The best time to visit is April to September. In June there are 16 h 29 of daylight, and in December, 7 h 30. Here is what it is, where it lies, when to come, how to get there and what else is nearby to turn it into a trip.

- Address: https://kokai.app/en/paises/europa/paises-bajos/old-observatory-main-building/
- Reviewed on: 2026-10-02
- Language: en

## In a nutshell

- **What it is:** University building and observatory in Leiden · History, Stargazing
- **Local name:** Oude Sterrewacht (hoofdgebouw)
- **Where:** Netherlands
- **Best time:** April to September.
- **Nearest airport:** RTM Rotterdam, 22 km as the crow flies
- **Opening hours:** Apr-Oct: Sa-Su 10:00-18:00; Nov-Mar: Sa-Su 10:00-16:00
- **Website:** [universiteitleiden.nl](https://www.universiteitleiden.nl/oudesterrewacht)
- **Run by:** Universiteit Leiden
- **Protection:** Protected heritage
- **Coordinates:** 52.15484, 4.48389

## What it is and where

main building of the Old Observatory, Leiden is a university building and observatory in Leiden (Oude Sterrewacht (hoofdgebouw)) in Netherlands (Alphen aan den Rijn).

It is in [Alphen aan den Rijn](https://kokai.app/en/paises/europa/paises-bajos/alphen-aan-den-rijn/), where this site lists 84 more places to see, 13 km from the centre.

Its coordinates are 52.15484, 4.48389; the nearest main airport is Rotterdam The Hague Airport (RTM, Rotterdam), 22 km as the crow flies. How to get around Netherlands (train, car, bus) is covered in [its country guide](https://kokai.app/en/paises/europa/paises-bajos/#moverse).

- [Where it is](https://www.google.com/maps/search/?api=1&query=52.154838%2C4.483887)
- [Directions](https://www.google.com/maps/dir/?api=1&destination=52.154838%2C4.483887)

- **Run by:** Universiteit Leiden
- **Protection:** Protected heritage

It is one of the [History](https://kokai.app/en/paises/europa/paises-bajos/historia/) and [Stargazing](https://kokai.app/en/paises/europa/paises-bajos/estrellas/) places in Netherlands. In [Kokai](https://kokai.app/en/) it is already on your trip map next to the places you save yourself, and it goes into a day's plan with one tap.

## When to go

The best time to visit main building of the Old Observatory, Leiden is **April to September**.

| Mes | Época | Hours of daylight |
| --- | --- | --- |
| January | Possible | 8 h |
| February | Possible | 9 h 38 |
| March | Possible | 11 h 31 |
| April | Best time | 13 h 39 |
| May | Best time | 15 h 28 |
| June | Best time | 16 h 29 |
| July | Best time | 16 h 04 |
| August | Best time | 14 h 27 |
| September | Best time | 12 h 23 |
| October | Possible | 10 h 19 |
| November | Possible | 8 h 28 |
| December | Possible | 7 h 30 |

In June there are 16 h 29 of daylight, and in December, 7 h 30. Daylight hours are calculated from the site's latitude for the 15th of each month; when planning a full day on foot they matter as much as the weather.

| What you come for | Best time | Possible |
| --- | --- | --- |
| History | April to September | October to March |
| Stargazing | — | November to March |

It is not the same trip whatever you come for: main building of the Old Observatory, Leiden has a different season depending on what you want to do here, and [Kokai](https://kokai.app/en/) puts it in the right month for you.

When to go to Netherlands in general, with its festivals and peak seasons, is in [its country guide](https://kokai.app/en/paises/europa/paises-bajos/#cuando-ir).

## Before you go to Netherlands

To enter Netherlands there are 6 things to sort out before you leave, starting with “Valid Spanish ID card (DNI) or passport”: they are all, with their deadlines, in [the Netherlands checklist](https://kokai.app/en/paises/europa/paises-bajos/#antes-de-salir). Currency: Euro (EUR); plugs: Type C and F · 230 V · 50 Hz (the same as in Spain); emergencies: 112 · 0900-8844 police (non-emergency).

In [Kokai](https://kokai.app/en/) you tick off the checklist inside your trip, and each item reminds you when it is time to do it.

## What is nearby

- [Heliometer building, Old Observatory, Leiden](https://kokai.app/en/paises/europa/paises-bajos/heliometergebouw/): Domed tower on the grounds of the Old Observatory in Leiden · 48 m
- [Fotografische kijker](https://kokai.app/en/paises/europa/paises-bajos/fotografische-kijker/): Observatory · 60 m
- [Hortus Botanicus Leiden](https://kokai.app/en/paises/europa/paises-bajos/hortus-botanicus-leiden/): Botanical garden in the Netherlands · 121 m
- [Pieterskerk, Leiden](https://kokai.app/en/paises/europa/paises-bajos/pieterskerk/): Church in Leiden · 411 m
- [Pilgrim Museum Leiden](https://kokai.app/en/paises/europa/paises-bajos/pilgrim-museum/): Museums and art · 418 m

Distances are as the crow flies. Everything else is in [the Netherlands guide](https://kokai.app/en/paises/europa/paises-bajos/).

## More in Netherlands: History

- [Rijksmuseum](https://kokai.app/en/paises/europa/paises-bajos/rijksmuseum/): museum in Amsterdam, Netherlands
- [Beemster](https://kokai.app/en/paises/europa/paises-bajos/droogmakerij-de-beemster/): former municipality in Noord-Holland, the Netherlands
- [Mauritshuis](https://kokai.app/en/paises/europa/paises-bajos/mauritshuis/): art museum in The Hague, Netherlands
- [Peace Palace](https://kokai.app/en/paises/europa/paises-bajos/palacio-de-la-paz/): international law administrative building in The Hague, Netherlands
- [Stelling van Amsterdam](https://kokai.app/en/paises/europa/paises-bajos/stelling-van-amsterdam/): fortification line in the Netherlands
- [Concertgebouw, Amsterdam](https://kokai.app/en/paises/europa/paises-bajos/concertgebouw/): concert hall in Amsterdam, Netherlands

Every Netherlands place under History, each with its season, is on [its page](https://kokai.app/en/paises/europa/paises-bajos/historia/).

## Frequently asked questions

### What is main building of the Old Observatory, Leiden?

It is a university building and observatory in Leiden (Oude Sterrewacht (hoofdgebouw) in the local language) in Netherlands.

### When is the best time to visit main building of the Old Observatory, Leiden?

April to September. In June there are 16 h 29 of daylight, and in December, 7 h 30.

### How do you get to main building of the Old Observatory, Leiden?

The nearest main airport is Rotterdam The Hague Airport (RTM), 22 km as the crow flies. From there, [directions](https://www.google.com/maps/dir/?api=1&destination=52.154838%2C4.483887) opens the route on the map, and how to get around Netherlands is explained in [its country guide](https://kokai.app/en/paises/europa/paises-bajos/#moverse).

### How do I add it to my trip?

With one tap. In Kokai it is already on the Netherlands map, next to the places you save yourself: add it to a day's plan, give it a time and, if you like, get a reminder when you pass nearby.

### What else is around here?

Nearby you have [Heliometer building, Old Observatory, Leiden](https://kokai.app/en/paises/europa/paises-bajos/heliometergebouw/), [Fotografische kijker](https://kokai.app/en/paises/europa/paises-bajos/fotografische-kijker/), [Hortus Botanicus Leiden](https://kokai.app/en/paises/europa/paises-bajos/hortus-botanicus-leiden/). The rest is in [the Netherlands guide](https://kokai.app/en/paises/europa/paises-bajos/).

Data from [OpenStreetMap](https://www.openstreetmap.org/way/52966204), licensed under the ODbL, and from [Wikidata](https://www.wikidata.org/wiki/Q17336073), CC0. More about main building of the Old Observatory, Leiden on [Wikipedia](https://nl.wikipedia.org/wiki/Oude_Sterrewacht). Daylight hours are calculated from the latitude. More in [credits](https://kokai.app/en/aviso/#creditos).