Omiya park is the most famous park in the Omiya area, but in my humble opinion it is far from the best. The lesser known Mihashi Sougo Park, 三橋総合公園, has more to offer and is easier to navigate.
The park is conveniently located off route 17. It is has plenty of free parking. There is an indoor community pool within the park, as well as other indoor and outdoor sporting facilities. There are 2 playgrounds, a running / cycle track and plenty of open spaces for children to play in.
The main playground boasts lots of different athletic type playground equipment. The main attraction is the ship in the centre of the playground, with its tall and curvy slides. It has a number of different climbing options, as you can see in the photo below.
Other equipment in this playground encourages climbing skills, such as the monkey bars, climbing wall and ropes. There is also a net climbing attraction, which proves very popular, as you can see in the photo below.
There is good shade around the circumference of this playground, as there are lots of trees making it ideal for picnicking in the summer. And by mid afternoon the playground is mostly in the shade. There are also picnic tables dotted throughout the playground. There are vending machines that sell drinks and there is a van that sells pot noodles. :-) There are toilets beside the car park, the tennis court and in the sports facility opposite the swimming pool.
Near the tennis courts there is another, smaller playground suited to toddlers and smaller children. It has swings as well as the roller slide pictured.
Another attraction of this park, for my kids anyway, is the abundance of insects. Today, for example, my kids and their friends (who we brought to the park with us), caught over 20 grasshoppers, beetles and crickets. :-)
Address: 5 Mihashi, Nishi Ward, Saitama City
Access by car: 10 minutes from the Yono exit of the Shuto expressway (Omiya route). Located at the intersection of R17 and R2