The statue of Jesús de la Misericordia, a 15-meter fiberglass thank-you note for the restored health of the gentleman who built Pacific Marlin, is easily reached via the gated driveway past the Pacific Marlin neighborhood or the ladder that winds its way from about 500 meters around the rocks on the northern point of the bay.
The steep walk takes about 30 minutes each way and leads to one of the best overlooks of the bay. You can walk 90 percent of the way for free; pay $1 to access the summit. Beware the snarling dog.
For a panorama from the antennas, take a bus toward Rivas [1] and ask the driver to let you off at Bocas de las Montañas. From there, head through the trees and pastures to the breezy and beautiful mirador (lookout)—an hour each way.
Some 1,700-year-old petroglyphs are accessible via a 90-minute round-trip countryside walk beginning east of the Texaco station. Consider asking for a local guide. Take a left (north), pass the school, and walk through a gate after about 500 meters; find the farmhouse and ask permission to cut through.
Follow the water pipes and the river until you find the stone with the carvings. Continue upstream to the (rainy season only) waterfall.
Links:
[1] http://www.moon.com/destinations/nicaragua/ometepe-and-rivas/rivas