ASUNCION, Paraguay — On a map of South America, Paraguay looks a little like the tucked-away footnote, no mountains or ocean coastline. But over my last two years as a Peace Corps volunteer, I’ve discovered a wealth of delights along the country’s southeastern border. So when my parents came to visit me on a break from the hustle and bustle of the Northeast, I decided to show them some of the startling vistas of nature, signs of man’s grand engineering, and spots of soothing tranquillity that Paraguay has to offer. Our trip started on a sweltering day in January’s midsummer heat. In Asuncion, we boarded a two-story bus with overstuffed seats and a wheezy air-conditioner and watched the scenery flow by through cracked windows as we headed to our first stop: Paraguay’s Jesuit missions, six hours south of Asuncion near the border city of Encarnacion.