Plečnik House -- the home of Ljubljana's chief architect! https://mgml.si/en/plecnik-house/
National Museum of Contemporary History -- understand Slovenia's 20th (and 21st) century history. https://www.muzej-nz.si/en/
Sts Cyril and Methodius Church -- orthodox church just outside the boundary of Tivoli Park
Tivoli park -- wander, wander, wander
US Embassy -- it's not what you would expect an embassy to look like.
Day trip to Kranj -- a place well off the American tourist path -- underground tunnels built by the Germans during WWII to protect town's population (esp factory workers), nice old town, gorge that runs through the middle of town that can be hiked/walked, Prešeren Museum (home/law office of Slovenia's national poet), Plečnik sites. There is a very interesting building at Koroška cesta 4 that has a purposefully rusted facade on one side with some shops/stores and a gleaming, modern, glass facade on the other side (that contains a library). My interpretation is that it marks the progression from the corrupt communist Yugoslav system to a bright, modern Slovenia built around knowledge. I love that building.