Mount Pinatubo is still an active volcano and it’s intensively monitored, so the site seems to be safe for trekking.
Mount Pinatubo is located about 90 km from Manila, so it’s a great option for a day trip.
The terrain is beautiful and caldera lake is also very scenic.
The hike is not difficult, but may be a bit demanding at the end.
For me, it was only a bit annoying, that we had to cross water (seasonal rivers and lakes) several times on the way; but that depends on the season, how rainy it was.
Anyway, I can highly recommend this hike. 🙂