If you are heading east from the temples of Asakusa, toward Tokyo Skytree, before the Sumida River is a park known as Sumida Park (Sumida Koen).
Just five minutes from Asakusa station at 1 Mukoujima Sumida-ku, Tokyo, Sumida Park is extremely popular in March and April for the cherry blossoms.
With over 1000 Sakura trees planted along the riverside, Sumida park was once a private park of a Shogun family.
The 8th Shogun of Tokugawa, yoshiee opened parts of the park for people to enjoy Hanami (watching the flowers or cherry blossoms bloom), Yoshie had more trees planted on both sides of the Sumida River.
While the park is not huge, aside from catching the park in its glorious beauty during hanami, it also offers great view of Tokyo Skytree from the distance.
Also, you can take the Tokyo Water Bus from the location as well.
And the good news is that if you are wanting to go to Tokyo Skytree, Asakusa Station that takes you there is real closeby.
If I have any advice for anyone wanting to visit the park, use the bathrooms in other locations (especially in restaurants or the station) as portable restrooms, despite the park having many of them, in the morning, many of them are locked up. And the lines just to get into one can get long.
Nevertheless, a park worth visiting if you are visiting the nearby Senso-ji Temple in Asakusa.