"This is the ancient site of Dubrovnik's metal forge, re-discovered by archeologists only about a decade ago. Before then this corner of the city had been a pile of construction rubble and ruins. The basketball court is actually the rooftop of a climate-controlled museum that has preserved the entire excavated site. See that sunken door on the right side of the court? That's the museum entrance. Walk in there and a Croatian archeology doctorate candidate will lead you on an hour-long guided tour through the catwalks suspended over the dig site.
I was there last summer with my girlfriend and two friends of ours and we decided to check out the museum out of curiosity, ended up being one of the most interesting parts of the whole trip. The ancient metalworks were extensive and the guide did a great job of explaining via his broken English exactly how each step of the process worked."
"We went on this tour too and it was excellent. The guide said he doesn't get many folks through the door because it is well hidden, so if you see this thread, go visit!... name of museum is The Foundry Museum (Gornji Ugao)."