I visited Anak Krakatau (a part of Ujung Kulon National Park) in January 2011 with my brother, my dad, and my uncle. We took a 2D1N tour package that includes a day-trip to Anak Krakatau, a stop at the Anak Krakatau's monitoring office near Carita, and a visit to the historic Dutch lighthouse called Cikoneng on the way back to Jakarta.
We flew to Jakarta from KL one evening and were immediately greeted by our guide (from krakatau-tour.com) and his driver who took us to a nice little hotel in Carita that same evening. Carita was a very small town and not at all touristy at that time. I'm not sure how it is today, but I remember we had to walk quite far from our hotel just to get to the nearest restaurant for dinner.
The next day, we had a simple hotel breakfast before the guide came to us and brought us to the jetty about 5 mins from the hotel. The boat ride to Anak Krakatau took about 1.5 hours one way, the ride was very bumpy as the ocean waves were very strong, definitely not a ride for those who are prone to seasickness.
We weren't allowed to land on the Anak Krakatau island itself because of the ongoing volcanic activity, so we had to land at one of the islands nearby called Sertung Island. Once arrived, we sat down by the black sandy beach while enjoying the impressive display put by Anak Krakatau. The lunch was pre-packed by the tour guide, so we sat down to have lunch while marveling the ongoing volcanic activity of Anak Krakatau on display right in front of eyes.
After about an hour on the island, the guide circled the main island as close as possibly allowed once before bringing us to a snorkeling spot nearby on the way back. However, being Malaysians who had visited beautiful islands like Redang, Kapas, and Tioman in Malaysia, the snorkeling session was pretty underwhelming to be honest.
We then went back to Carita, then to Jakarta. On the way back to Jakarta, we stopped at the seismic office called Pasauran Sesmograf to look at the live seismometer that was used to monitor Anak Krakatau's activity, then we stopped at the Anyer Cikoneng lighthouse, before reaching Jakarta.
Despite not being able to land on the island and hike the volcano because of the activity at that time, I thought that overall, it was an even greater experience to visit while the volcano was active, and just for the OUV of these volcanic islands alone, Ujong Kulon National Park definitely deserves the world heritage status.