One of many Island mysteries is the curious relocation of Oceanic 815 wreckage which occurred between the time of the pilot and the subsequent episode, Tabula Rasa. My understanding is that several months passed between shooting the pilot and the episode 2; during that time the wreckage was moved from the beach to Dillingham Airfield, just across the road. When the plane was returned to the sand it was setup in a location further west. A comparison of the following two screencaps, the first from the pilot and the second from episode 8, Confidence Man, illustrate the move.
Although our tour stuck to the region where the pilot was filmed, here's a blow-up (no pun intended) of the general area where most of the later crash beach scenes were shot.
The following screencaps feature scenes from several season 1 episodes which occur on the crash beach.
This shot was taken from our van, emphasizing the proximity of the crash beach to the road.
File under art imitating life -- as season 1 filming progressed the winds picked up on the beach (visible in several episodes) and the decision was made to have our castaways move from the unprotected crash beach to an area with calmer winds and less dangerous surf. The migration was written into the twelfth episode of season 1, Whatever the Case May Be.