Lower Seletar Reservoir is a beautiful reservoir just next to Yishun New Town. The best places to enjoy are the Lower Seletar Reservoir Park at Yishun Avenue 1 and the Lower Seletar Reservoir dam also at Yishun Avenue 1 (more information and photos are at my VT Seletar page).
Yishun New Town is a big housing estate consisting of many housing flats where the people of Singapore stay. This place used to be a rural area years ago, but is now very modernised. To reach Yishun New Town, the best way is to take the MRT subway system to either Khatib or Yishun MRT stations. It is very safe to walk around and explore Yishun New Town to learn how the local people live, very nice place.
For the best views of Lower Seletar Reservoir, go to housing estate block 816 along Yishun Avenue 1 just next to the Yishun Stadium and Lower Seletar Reservoir Park. Go up to the top floor (11th floor) via the lift and you will be treated with beautiful sceneries as shown in the photos.
There are several nice parks located among the housing estate of Yishun New Town. There is a Yishun Town Garden near to the Northpoint Shopping Centre at the Yishun MRT Station and a neighbourhood park at Yishun Avenue 7. There is a bigger Yishun Park along Yishun Central, Yishun Ring Road and Yishun Avenue 4. The best park in Yishun has to be the Lower Seletar Reservoir Park located at the junction between Yishun Avenue 1 and Lentor Avenue as this park has beautiful views of the Lower Seletar Reservoir. More photos are at the travelogue section of this VT page.
There are three major rivers in the Nee Soon area, namely Seletar River (now become a freshwater reservoir), the Khatib Bongsu River and the Simpang River. You will see the Khatib Bongsu River and Simpang River during trekking in the Nee Soon area. The Seletar River is more easily accessible along Lentor Avenue and there is even a park next to it for recreational activities.
Near the end of the Simpang Grassland trek is the sea area. Here, you will find the isolated Tanjong Aru beach which is especially nice during low tide. Across the other side of the water is the State of Johor, Malaysia.
Simpang grassland located in the Nee Soon area is one of the last remaining wide grassland areas in Singapore. You can explore this grassland by doing some simple trekking during the weekends (the Singapore army may be using this place for training during the weekdays). The entrance to the grassland is at the corner of the heavy vehicle parking lots at the end of Yishun Avenue 7 near to the Compaq factory building.
Khatib Bongsu is a very secluded area in Nee Soon and the entrance to this place is a track road along Yishun Avenue 6 just opposite North View Primary School and HDB flat block 405. You can do some simple walking to admire the natural scenery here. I will show you some photos of Khatib Bongsu in my travelogues of this VT page.
There is a Chinese temple at Khatib Bongsu, but I heard it will be demolished soon. Anyway, I managed to take a photo of the temple when I was there.