Happening at OLA

Astronomical Observations

Every night at 21h30. During this two hour session, learn to find the polar star, identify the constellations and know their legends, relate stellar colours with their ages, observe star clusters, nebulas and distant galaxies with the help of our telescopes.

Astronomical Saturdays

Every Saturdays afternoon, from 16:30 to 17:30, OLA offers activities for children where the young astronomers learn more about science and astronomy in an entertaining and relaxed way. Verify here the calendar of activities.


Moonwatching & Stargazing

17th August and 14th September. In collaboration with Portugal Birds & Trails, OLA organizes two events connecting stargazing with birdwatching by night.

Workshop on deep sky photography

31st August. A three hour session where the participants can follow and experiment the steps of acquiring deep sky images and learn how to process them. The participants use the observatory main telescope and become, for one night, the astronomers on duty.


Workshop on landscape astrophotography

24th August. During two hours the participants will learn the basic camera definitions that will allow them to acquire night photos. The session will start with a brief theoretical introduction followed by exercises in OLA’s field.

Photography exhibition: Sky & Sea

From the 11th May. Exhibition of astronomical and underwater photography by professor Pedro Ré.


Observatório do Lago Alqueva - OLA

Discover Monsaraz's night sky and be amazed with the Universe

Located within of the Dark Sky Reserve in Alentejo, OLA aims that our visitors find a pleasant place to discover the Universe and learn more about Astronomy and astrophotography, in one of the areas of Europe most protected against the light polution of big cities.


N 38 ° 26′ 35.5″ W 7 ° 22′ 01.5″
(+351) 960 361 906

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Other services

Activities for senior groups

The observatory offers a wide range of astronomy related activities having the seniors in mind.

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Activities for schools

The observatory offers a wide range of astronomy related activities having the school programs in mind, from elementary to high school.


Equipment rental

The observatory offers a wide range of astronomical equipment for rental, such as telescopes, mounts and cameras. Click here to know more.

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External observations

OLA has observation sessions for large groups outside the observatory. In case you plan to have a session in the facilities of your company, school or in any event your are organizing, we have at your service the experience of our sky guides and our equipment.


Main Building

Houses the reception and shop, the bookshop and the auditorium. It has a dome with a telescope for the night sky observations. The visitors can enjoy the view onto the Alqueva lake and village of Monsaraz. On the foreground the sundial where one can learn how to measure the local time from the direction of our shadow.

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Observation Platforms

The observation platform is located at the center of the observatory field. It is used as a support structure for large groups of astronomers and has a central role on the organization of star parties. It consists of a solid surface where tripods and pillars can be installed for telescopes and binoculars as well as other support equipment and with access to the electricity grid.


It is the main room where events such as talks, courses, workshops or even concerts happen. There are always two photography exhibitions displayed from either young or well known authors. It is possible to rent the auditorium for meetings, conferences or anniversary parties.

Observation Dome

This is the dome where the main telescope resides and where the most detailed work and images are performed.


Conjuctions and Lunar phases Solar and Lunar Visibility