21st Century Museum of Contemporary Art

SANAA - Kazuyo Sejima and Ryue Nishizawa - completed this in 2004 as a circle 112.5 metres across, entirely glass-walled, single-storey in appearance, with entrances on four sides so that there is no front and no back and no hierarchy of approach. Rooms of different heights and proportions sit inside the circle like a small town, with corridors between them, and the free zone runs through the middle so the building works as a public route rather than a destination. The permanent work everyone knows is Leandro Erlich's Swimming Pool: from above it is a pool of water, and from the room below - reached through the ticketed zone - visitors stand under the surface and look up at the people above. Other permanent pieces include a colour-glass room by Olafur Eliasson on the roof. The museum sits directly beside Kenrokuen, which was the point of the siting.

What you actually see

• A circle with no front - 112.5 metres of glass with entrances on four sides.
• Rooms like a town - galleries of different heights set inside the circle with lanes between.
• The Swimming Pool - Erlich's work seen from above and from beneath the surface.
• A free public route - the central zone open without a ticket.

When to go

All year. Two to three hours. Closed Mondays.

Honest expectations

The underside of the pool is in the ticketed zone and often needs a timed slot booked ahead - many visitors only get the view from above. Closed Mondays. Temporary exhibitions vary in quality. The building is busy and glass carries sound.

Nearby

Kenrokuen is directly across the road; Nagamachi is west.