Walk across the bridge
The Market Street Bridge takes you across the Susquehanna River from the historic district of downtown Wilkes-Barre to what is technically Kingston, Pennsylvania on the other side. You'll have nice views of Wilkes-Barre from the bridge and the four arches at the ends of the structure are each topped with a limestone eagle. The bridge was built in the late 1920s and is made of concrete and granite.
FM Kirby Park
On the north side of the Susquehanna River (opposite from downtown Wilkes-Barre), you'll find a nice green space known as FM Kirby Park. I believe that as soon as cross the river you're technically in Kingston, PA, but since it's literally a three minute walk across the Market Street Bridge, we'll call it close enough. There's a nice lake and plenty of grass to lounge on along with some nice bike/walking paths.
King's College is a small, but interesting campus. If you're visiting the Luzerne County Court House building on North River Street, you should definitely scoot across the street for a quick look at the campus. The school was founded in 1946 by the congregation of the Holy Cross of the University of Notre Dame and has an approximate enrollment of about 2200 students. There is a large Christ statue reminiscent of the one on Corcovado in Rio de Janeiro on top of the Administration building and a few other interesting monuments, statues and landscaped spaces to see. The statue below is of Leo the Lion the school mascot.
Check out my King's College travelogue for some more pictures of the campus.
Luzerne County Court House
The Luzerne County Court House building in Wilkes-Barre is one of the most impressive buildings in town. It's located right along the river's edge near the campus of King's College. When I visited in July of 2005, they were working on the dome, but it still was quite a striking building.
The architecture was heavily influenced by the World's Columbian Exposition which was held in Chicago in 1893 and began the "White Cities Movement" emphasizing the "Beaux Arts" architectural style popular during this time.
There is a nice green space in front of the building with some interesting monuments and statues and nice landscaping and flowers.