worth

be worth + noun
The museum is worth a visit.
The museum worth a visit. (wrong)
The museum worths a visit. (wrong)
The museum is worth to a visit. (wrong)

be worth + -ing form
The museum is worth visiting.
The museum is worth visit. (wrong)
The museum is worth to visit. (wrong)
The museum is worth to visiting. (wrong)

be worth + it
The ticket is expensive, but it is worth it.
The ticket is expensive, but it is worth. (wrong)
The ticket is expensive, but it is worthed. (wrong)