step inside world’s largest LED dome by collcoll illuminating prague planetarium

New LED dome lights up the Prague Planetarium interior

Czech architectural studio collcoll introduces unique LED technology, transforming the Prague Planetarium into a large illuminating dome. The Prague Planetarium has undergone a major modernization that goes far beyond just replacing its projection equipment. The renovation of the protected building, designed by architect Jaroslav Frágner in the 1950s, was complex. It required removing layers of interventions from recent decades to make way for the installation of revolutionary LED projection technology. The largest LED screen of its kind in the world. At the heart of the project is a new hemispherical screen from the American company COSM, 22 meters in diameter, with an incredible 45 million pixels. Visitors can experience an immersive spatial illusion with extraordinary color depth and realism.

all images by BoysPlayNice

collcoll redesigns the auditorium for immersive viewing

The central Zeiss Jena projector was moved outside the main hall by agreement with heritage conservators, freeing space for a new auditorium design. Architects from collcoll studio designed a stepped geometric layout that visually lifts the audience above the horizon. Capacity increased by 20% to 277 seats, with a spatial arrangement supporting comfortable and safe movement. The seats were custom-designed with a Czech manufacturer, and they are now adjustable, ergonomic, and comfortable enough to keep visitors attentive. Acoustic treatment hidden behind the projection dome further enhances the illusion of infinite space.

The installation of new technology required new energy and technical facilities, integrated into the building with maximum respect for its protected structures. Cooling and heat recovery were designed considering the planetarium’s location in the heart of Stromovka Park. Heat from the screen is stored in six deep wells (each 200 m deep) in summer and used to heat the building in winter. The dome itself has a thermal output comparable to three family houses, so the heat is reused within the building.

new LED dome lights up the Prague Planetarium interior

Historical preservation merges with future-forward design

The renovation also affected the foyer and facilities. The original exhibition at the entrance was replaced by a circular LED screen serving as an additional presentation surface. A newly designed cloakroom separates incoming and outgoing visitor flows, increasing comfort. Over the summer of 2025, a new simulator exhibition in the basement is set to open, along with a shop at the new exit, after completing outdoor landscaping. An inappropriately placed ramp will be removed from the adjacent rosarium, simplifying barrier-free access through the shop. This modernization positions the Prague Planetarium as a world leader in immersive education and culture with its unique LED dome technology, offering visitors an unprecedented visual experience of the cosmos. 

collcoll studio redesigns the auditorium for immersive viewing

viewers experience deep color and spatial illusion

a 22-meter LED dome redefines spatial projection

seating redesigned for ergonomics and adjustability

geometric stepped seating raises audience above the horizon

energy systems adapted to preserve the protected building

integrated acoustic treatments enhance spatial perception

project info:

name: Prague Planetarium
architect: collcoll | @collcoll.cc

design team: Adam Kössler, Krištof Hanzlík, Libor Mládek, Michal Fousek

client: Observatory and Planetarium of Capital City Prague | @planetum.cz

location: Královská obora 233, 170 00 Prague, Czech Republic

dimensions: 22 m screen diameter 45 000 000 LEDs screen resolution

photographer: BoysPlayNice | @boysplaynice

project management: CManagement [Arnošt Táborský, Dan Kouba]

technical supervisor: Jiří Cís

energy management: TO SYSTEM [Jaroslav Smejkal, Jakub Janďourek]

ventilation: Atrea [Barbora Paříková, Zdeněk Zikán]

cooling: Michal Ježek

structural engineer: Štěpán Thondel

lighting concept, electricity: sysloop engineering [Miroslav Frolec, Anatolyi Obryn]

acoustic design: Aveton [Dominik Cvetler]

acoustic consultation: Petr Roll

acoustic insulation: A.W.A.L. [Kateřina Volšíková]

fire safety: Ilona Muziková

sanitary: TZB-BLOCK [Jan Smrček]

server room: Altron [Jakub Odlas]

power line connection: Pring [Jan Vočko]

geothermal wells: Gerotop [Tomáš Kuchta]

landscaping: her architecture [Alice Boušková]

geodetic survey: Pavel Keprta, Jan Kopecký

LED projection technology: Cosm

dome structure: Spitz

LED technology, projection software: Evans & Sutherland

demolition and site preparation: Technical department of the Planetarium

building works: Rextron

steel structure: Karel Krejčíř

seats fabrication: Kinoexport

LED lighting: sysloop engineering

LED screen foyer: Loko Trans Media

electricity: Galenit

environmental controls, ventilation: Bohemik

heating: Regultherm

measurement and control: STIFRA Plzeň

ICT: Sistel

ventilation: Croatherm

scaffolding: Peri Up

geothermal boreholes: Artemia

designboom has received this project from our DIY submissions feature, where we welcome our readers to submit their own work for publication. see more project submissions from our readers here.

edited by: christina vergopoulou | designboom