After breakfast, we'll warm up to challenge the big mountainous pass. Hai Van Pass is not really long pass, but the route is scenic, and it curls around a mountainous spur above the East Sea on the central coast. The pass is a stunning stretch of highway that winds through the Truong Son mountain range. It is 500 m above sea level, and the up/down slope ranges from 5-10%; there will be plenty of breaks along the way to take in the views and snap some photos. At the top, we can see many old military bunkers, radio stations, and traditional gates. Capture plenty of pictures before we ride down the pass southwards along the coast to Da Nang. Stop for lunch at a local restaurant. The afternoon's ride is on the flat coastal roads to Marble Mountain, where we hike up the hills to discover many natural caves in which Buddhist sanctuaries have been built over the centuries. Afterwards, we'll continue cycling to Hoi An, an ancient town in the late afternoon.