Is there no support for height data? I work in a museum and tourist information point that's ''underneath'' a major railway station terminus forecourt. People walk out of the station building into the outdoor cab rank, and latitude/longitude would tell them that they were inside the museum. Location data should be able to tell them that the "invisible" museum is twenty feet straight down, below their feet, and they they need to scout about for a way down.
Similarly, the station is built into the side of a steep hill, and we get a steady stream of lost people coming in from the road outside looking for it, who don't realise that the station is a couple of storeys up the the air, above the brickwork in front of them.
I appreciate that altitude isn't as important as lat/long, but it seems odd to have no way of entering the data for the cases where it matters.