One of the most interesting places I've stayed yet - a two story flat on the roof of an old italian building. It is several minutes away from the tram station, which can get you inside the city in 15~ish minutes, right besides the railway station and the bus station where you can get your airport bus, so it is very easy to get around town and the whole region.
The appartment has everything you need for a short stay, but be brief with showers, unless you want to finish them with cold water.
It is perfect if you have little luggage, but if you have sizeable baggage, it will be cumbersome to get it through the stairs, as the building is quite crammed.
I would stay again, if I will ever be in the Bergamo region again.