Humans have been inspired by the Alfar (and the Sidhe, and the rest of those diverse races, for millennia. We have also been lost many times in their realms, often with disastrous results, or so the stories go. Warning tales abound regarding humans who go to live in the country of the Fair Folk, only to return to find that everyone they knew is dead, or old and grey. Or they themselves have aged beyond their years; it is almost the signature of elven places.
Time and Seasons:
Time flows very differently in Ljossalfheim, more so than in any other of the Nine Worlds. Day length is variable, and changes randomly. When Sunna and Mani pass overhead, they too are drawn into the magical web of the Alfar, if only temporarily, and although they always make it out the other side on time (or a great many folk would be very angry), their normal effects are distorted.
Seasons will vary, also, depending on the area. Unlike other worlds, where there is a distinct "year" that turns (if only subtly, in the case of Muspellheim and Niflheim) similarly for every place in the world, in Alfheim it may be summer in one place, and winter in another. Generally the seasons follow each other, but any one area may be on a different cycle depending on the whim of the House that rules it. They are also not above "freezing" one season for a while in order to enjoy it further, although this takes a good deal of work. Some places do seem to be permanently "frozen" in season.
Also variable. Ljossalfheim is more of a manipulated world than any other; the very stuff of the earth is continually being changed around, reworked, glamorized, unglamorized, and generally transformed over time. There are many villages in Alfheim, and many thousands of peasant huts where the poorer faery-folk live. However, the fact that the land and its residences change so often means that it will be much more difficult to magically extract a map from the Big Library. In fact, it may mean that the second time you visit, things are not where they were the first time.
No one knows exactly how the Alfar got into the Nine Worlds. We are quite clear, however, that they are not native, unlike the Duergar. They came into the Nine Worlds from their original home - which may be the same place as the Sidhe, or not - and were given Ljossalfheim by the Aesir. They are on excellent terms with both the Aesir and the Vanir, but don't get on well with the Jotunfolk, whom they consider to be completely irredeemable barbarians.