Umino Kouen is about a 25 minute drive from Yokosuka (heading up 16 towards Yokohama - somewhat close to Costco).  There are two large (off leash) dog parks there.  They are located right outside the train train station.  The [script removed]
It would be great to arrange a meet-up with other dog owners once the weather get nice.  The whole park there is beautiful.  There are tons of walking trails to jog along or walk your dog. 

During the summer, you'll find people playing volleyball all along the beach.  The beach is itself is very family oriented.  The one negative is that there is a lot of seaweed.  But, the water is very shallow and great for small children.  The water was also very warm during the summer months (probably from all the little kiddies peeing in the water!). 

It seems like there is always a flea market going on at least once or twice a month.  People fill the parking lot, selling off all their used stuff.  There are also a few vendars set up ready to feed your hungry belly!

When the weather is nice, you'll find tons of people out barbecueing with friends and family.  You can rent out a grill / picnic table space.  I think they even sell food for you to grill!  I'm not sure how much it costs though.....but the smell definetly lures you in!

Here is the main website:

http://www.umino-kouen.net/index.html

Use google translator to translate the page (Just cut and past the url into the box - be sure to select translation from Japanese to English):  http://translate.google.com/#

Big beach:  http://www.umino-kouen.net/shisetsu.html   and   http://www.umino-kouen.net/kaisuiyoku.html

Map of Umino Kouen:  http://www.umino-kouen.net/parkmap.html

Check it out!  Parking is 300Y / hr.  I'm not sure how much train fair would be from Yokosuka-chuo.  It's a popular place in the summer, so you'll want to get there somewhat early to get a parking spot! 

If anyone is interested in meeting up at the dog park, let me know!  I have two dogs that "love" the dog park!

Sorry guys. I thought the need to step in and just delete the unnecessary posts. If someone is trying to promote a positive event/information/resources, lets not bash the person by posting unnecessary comments. If you dont agree, just dont reply. If you have something worth while to respond then do so, but leave the crap off the site.. Thanks Wilson for stepping in.

cool dude Ill keep it positve. I just say how I feel you know, Im free from any PC or cultural sensitivity and hate so sometimes I offend. Thanks for keeping me in check.

Park sounds nice, I'd like to go sometime I also have a dog that loves dp's!

I'd be happy to bring the Pug.... he'll be beside himself with joy.

Great! I'll post again once the weather gets warmer! My Ralphy and Tippy will love to have new friends to play with!