It had snowed (!) the night before in El Alto and the mountains, so the drive was beautiful the whole way. There's one point where you have to cross the lake on a ferry (no bridge) and each bus gets it's own little personal ferry, which I thought was adorable.
Copacabana is relatively touristy these days, but is still a very important town to Bolivians due to it's Inca heritage and the town Cathedral which houses some of the country's most important religious artifacts.
Apparently every time someone buys a new car in Bolivia, they decorate it (kinda like a parade float...lots of flowers) and drive it to the Cathedral for the priest to bless the car -- unfortunately this mostly occurs on the weekend so I was a day too late to see the real procession :(
The ferry ride across the Lake to the Isla del Sol is slooooooooooow and freezing but super pretty. According to mythology, the Isla del Sol is both the birthplace of the sun and the location where the first Inca's came from.
I visited a number of old Inca ruins, including Pilko Kaina which...assuming I understood this right...is the first Inca palace (where the very first two Incas lived). The island is also beautiful -- it's covered with Inca terraces for farms and in the distance you can see the Andes across the super-blue lake. There are no cars and it's really serene...until the donkeys/burros start making noise.
Monday I left the entertainment of La Paz behind, and took a bus north to Copacabana on the shore of Lake Titicaca.