The beautiful marble cave you see above is located on a peninsula of solid marble bordering Lake General Carrera, a remote glacial lake that spans the Chile-Argentina border. It was formed by 6,000+ years of waves washing up against calcium carbonate. The smooth, swirling blues of the cavern walls are a reflection of the lake’s azure waters, which change in intensity and hue, depending on water levels and time of year. Continue reading for more majestic and breathtaking caves you can actually visit.