The large glass dome at the very top of the Reichstag has a 360-degree view of the surrounding Berlin cityscape. The main hall (debating chamber) of the parliament below can also be seen from inside the dome, and natural light from above radiates down to the parliament floor. A large sun shield tracks the movement of the sun electronically and blocks direct sunlight which would not only cause large solar gain, but dazzle those below. Construction work was finished in 1999 and the seat of parliament was transferred to the Bundestag in April of that year. The dome is open to visitors by prior registration.