The Royal Chapel of the Invalides, also known as the Church of the Dome, was built between 1677 and 1706 according to the plans of the architect Jules Hardouin-Mansart. The church has the simple shape of a Greek cross set in a square plan. Each of the exterior facades is composed of two superimposed levels underlined by porches topped by triangular pediments. The dome is 90 metres high and is topped by a lantern, bringing the total height of the building to 101 metres. The dome is set on a high drum with two floors of unequal height decorated with windows. The windows on the second level, invisible in the church, illuminate the interior framework.