I visited Alas Purwo* National Park in January 2008. I drove in as far east as I could before the road disappeared into a long stretch of sand. I didn't have 4WD so I didn't chance getting stuck in the sand alone and in the middle of nowhere. I camped out on the beach. I recall that the beaches were nice except for the massive amounts of trash. When I inquired I was told it was due to the rains which wash down copious amounts of trash around this time of the year. Same phenomenon on the coastal stretch facing Java of the Bali Barat National Park.
* Alas Purwo is where, according to Javanese myth, the world was created. According to the myth, this is where the world emerged from the ocean.