Having experienced the 1965 eruption first hand, I made a point of including a visit to Taal volcano during my trip back to the country of my childhood.
Wherever you go within 30 minutes of the lake, be prepared to be followed at every step by someone offering you services of some sort or other pertaining to the island. This continues, no it almost even gets worse once you actually reach the volcano island. The vendors will want to rent you a horse, a hat, sell you water, take a picture, anything they can think of. I don't blame them. They have to make a living, but it can be annoying for the tourists.
I heartily recommend doing your research before you get there. There are apparently ways to book a tour before you get there. They may not be the cheapest options, but when you wait to hire a boat until you're there you have little idea of the quality of the services provided.
We opted for a tour provided by the Taal Lake Yacht Club. They offer a number of options. We were satisfied with what they provided us.
On the island itself, you have to decide whether you want to walk up to the top or take a horse. Walking takes about 40 minutes, a horse about 30 minutes. The way up is hot and dusty either way. You don't have to be an athlete to make it, but you shouldn't be in sub-average shape, either. A warning about the horses, though: They are not very large and normally really too small for an average westerner. That doesn't stop the horse owners trying to put anyone and everyone on a horse, though.
All in all, I'd say it's worth a visit. There are other volcanos that look more like a volcano, but this one really is special because of the island within a lake, within an island, within a lake, within an island, inside the Pacific Ocean. It might be worth your while to look into the special tours that take you off the beaten track and maybe even down into the island lake.
And for me, of course, it was special because this volcano woke me up in the middle of the night in 1965.
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