YanivLahav created this spectacular view of one of the natural wonders of Portugal: the famous caves of Boca Inferno near Lisbon. They lie near the beach city of Cascais, just west of the mouth of the Tagus River, on a stretch of coastline known as the Portuguese Riviera. A short distance from Lisbon, the caves are a popular tourist attraction. The famed beaches of Cascais, some of the most popular in Portugal, lie just to the east of the caves. The entire area is considered part of the Grande Lisboa region.