Here's what I do:
10am to 12pm -- Explore the Crystal Cave.
Not many people heard of the Crystal Cave in Kupang or know about it. Even a lot of the locals have never been there. But, that doesn't mean you shouldn't go! It's located in the middle of nowhere, so make sure you have a local guide who knows the area very well.
Even the entrance to the cave is hard to find. There's no path or whatsoever!
Once you're at the front of the cave, please make sure to wear comfortable shoes or sandals as you'll need to go down to the cave, crawling from one big rock to another. During rainy season, the rocks can be very slippery, so it's probably better to walk barefoot.
It's pretty dark in here, please don't forget to bring a torch!
After a few minutes of walking down to the bottom of the cave, you'll be greeted by an amazing view. A lagoon with crystal clear water awaits you!!! It looks like a private swimming pool, but more beautiful because of the light that comes from the above, shining into the lagoon and reflecting the colour of the rocks and water. Very pretty! And oh, as the water is very clear, you can see all the rocks underwater and also another underwater cave that will give you an eerie feeling.
It is just amazing.