Secret
Astronomy Park
It hides out in the western suburbs of Ha Noi. Maybe 15km from the Old Quarter, which means a one-hour Grab ride in rush hour. Might be a bit far, but if you are in the area (staying at JW Marriott, say, which is a much closer ride), it might be worth it. It is a park around a reservoir. It's a good place for a walk and a picnic under a shady tree. A couple of the tree groves start to feel like real jungle.
It gets its name from the displays of astronomy around the walking path in the park. Some are educational; some are a little more fun.
I was there at noon. It was almost empty. One family having a quiet lunch on a blanket in the shade. Apparently it picks up closer to sunset, which makes sense given the heat here.
Neighborhood: Ha Dong District
Address: P. Nguyễn Văn Luyện, Dương Nội, Hà Nội