The Vatican has miles of corridors with ceilings that were frescoed in centuries past by artists,
many of whom are little known and whose works are highly under-appreciaed.
So when you visit the Vatican Galleries, look up now and then, even when you aren't in the Sistine Chapel !
Like the mosaic floors we walk on in many of the galleries (next image), these works of art took many hours and much effort to produce,
and are barely noticed by most visitors.