20190703_163352 R in the small-leaved linden alley
20190703_163222 Raudone castle tower
20190703_162036 Old school desk in Raudone castle
P1020761 A dark-detecting solar-powered device?
I guess the point of this gadget demonstrated at Maker Faire 2008 is that it lights up when it detects dark.
The description of the Simple Solar Circuits group of exhibits from Evil Mad Scientist Laboratories says: "We demonstrate a few simple circuits -- that you can build yourself -- to make small solar and battery-powered night lights, garden lights, and decorations for Halloween."