Raintrees Sandcastle at Birch Bay is nestled at the edge of the water on Birch Bay Drive, which is the main road through the charmingly sleepy town, making it the quiet center of events. The Sandcastle at Birch Bays richly-decorated vacation condos feature lavish appointments and bay or golf course views. On-site dining includes Shores Restaurant and Tradewinds Cafe. Minimum age required at check-in is 21. Check-in is located at the front desk. It is open 24 hours for your convenience. Minimum age required at check-in is 21. Check-in is located at the front desk. It is open 24 hours for your convenience. Relaxation and fun can be found in Birch Bay. Over breakfast, enjoy bird watching for eagles and herons or lunch on the shores of Birch Bay while kids splash around in the Northwest's warmest tide waters. You could also take a bike ride while enjoying views of Mt. Baker and the San Juan Islands.