This is a great ride because of the variety; Flats and climbs, City and serenity. There are dedicated bikes trails along the Lakes Washington and Sammamish. At the south end of Lake Sammamish there is a short section on of busy but safe road travel that ultimately gets you to the bottom of a challenging climb at the Cougar Mountain Zoo. This climb is a good reminder to protect your health as it’s a rather good huff to the top. Take the optional additional climb to the summit of Cougar Mountain. It’s a very fun descent all the way way back to Hwy 405 - particularly good on Forest Dr SE and where it connects into Coal Creek Pkwy. From there, this map takes you directly through downtown Bellevue, but there are options if you prefer to avoid the city riding on NE 8th St. Once you get back to the 520 bridge it’s all gravy. Overall this is a very safe ride but plan on wearing bright colors and using a flashing lights for visibility.