Within Hawaii Volcanoes National Park lies the volcano of Kilauea – one of the world’s most active and accessible volcanoes. If you want to see molten magma etc this is the place to go. Except of course that it isn’t always erupting and the eruption isn’t always convenient or safe to see. Unfortunately, when we were there, the only visible “red spot” required a helicopter ride – and we were left with the remains of a previous magma flow crossing (and blocking!) a road (photo). Luckily we saw our “red spot” on a later trip to Etna albeit not as impressively as we would have liked.
There are web sites (eg http://www.volcanogallery.com/Volcano_news.htm) which provide you with up to the day information during an eruption if you are able to drop everything and take in the sights at their optimum time (However I understand that there are a lot of volcano watchers in the world and that transport can get pretty full at these “best” times). The IUCN review dated 1987 states that the volcano has had “more than 50 recorded eruptions in the last 33 years up to 1985”. There does not appear to be an eruption as of the date of this review (Jan 2006)!
If, like ours in summer 1987, your visit to the park doesn’t coincide with a major volcanic event, the Park still offers plenty to see both in terms of the main crater and magma flows and also in terms of fine mountain scenery (Mauna Loa is 13600 ft above sea level) and seashore views, forest and bird life. There is also a Hawaiian “aboriginal” “temple” at Waha’ula Heiau (which is said to date from 1275CE) – but, although inside the Park boundaries, this is NOT included in the criteria for the site designation which are purely “Natural”. Another aboriginal archaeological site on Hawaii a few miles away at Pu’uhonua o‘Homaunau was rejected for inscription by UNESCO in 1987 – the same year that the Volcanoes Park was accepted.
Remember that a trans-Pacific flight will “drop” you several islands away at Honolulu on the island of Oahu so this park can’t be picked up that easily on a quick Pacific stop-over. But the Hawaiian Islands justify more than this anyway and it would be a shame just to visit Oahu whilst you are in the area.