As a kid my Catholic parents explained to me the custom on Holy Thursday of visiting different churches to pray and admire the decorations of the altars of repose.
In Rome everybody does the same on the evening of Holy Thursday, the so-called "seven churches" of Maundy Thursday (as everybody here tries to visit at least that many that night and I heard the morning after, too). This year we saw nearly twenty.
At almost 11:30 p.m. I stumbled up this step for my last visit of the night. You never know what the Holy Ghost has in store for you. I got into the museum of the old sediari here in the sacristy which was great after seeing many times the museum in the Lateran Palace of the old Papal Court where one can see a real sedia gestatoria, albeit a few of them.