Summertime: A Guide to Entertainment, Activities And Excursions : Discoveries : * If you’ve exhausted all of the usual tourist spots, it’s time to visit some destinations along the unbeaten path. : A Garden Next to a Big Plant

In the middle of Van Nuys is an oasis of sublime visual beauty and peace.

And it’s right next to a huge sewage plant.

The Japanese Garden at the Donald Tillman Water Reclamation Plant in Woodley Park is a wonderful place to give your eyes a break from the chaotic urban landscape. Built as part of the reclamation project that was finished in 1984, the 6 1/2-acre formal garden is a graceful mix of grassy, lake, marsh and rocky environs.

There are lovely bridges, delicately arranged rock formations, stone lanterns, trees in a bonsai style (only one is an authentic bonsai--more would have been prohibitively expensive), patches of flowers and a teahouse.

Each section was created by famed garden designer Koichi Kawana to express a specific theme, according to the helpful docents who give free, hourlong tours of the park. The tours end with a quick look at the huge, high-tech plant, which is almost invisible from the park and, happily, emits few foul smells.

The sole intrusion on this peaceful atmosphere is noise from planes taking off and landing at nearby Van Nuys Airport. It’s too bad the garden is not as restful for the ears as it is for the eyes.

The Japanese Garden is at 6100 Woodley Ave., Van Nuys. Tours are given on weeknights at 6:30 and during the day on Tuesdays, Thursdays and Saturdays. The garden is open for unguided wandering on the second Wednesday of every month from 10 a.m. to 3 p.m. Reservations are required for all visits to the park. Information: (818) 989-8166.