It's a good base camp for exploring the Tenorio Volcano National Park or Lake Arenal but the town itself isn't very interesting. The only building that was worth photographing at Tilaran was the church. The surrounding countryside is agricultural and pastoral, albeit that the Arenal and Tenorio National Parks quickly take you back into a more mountainous environment. In this area you can explore coffee, peanut and macadamia nut plantations, or horse and cattle ranches.
11 km down the road to Monteverde be sure to stop at the magnificent Viento Fresco waterfalls (or you can go there on horse back for an experience that is 100% Costa Rican). Thewindsurfersamong you will like Lake Arenal where there is wind from November to April. It's also a good place for birdwatching.