Help surprise my girlfriend

It’s my girlfriend’s birthday on our trip to your island, and I really want to surprise her with a special experience.

We (21F&22M) haven’t seen much of each other the past half year because of work, and I thought about making something special out of her birthday this year. If any of you have some recommendations or ideas I would love to know:)

Practical:
The trip takes place in start of July and in the northern part of Sabah

Thank you!