Natural Pools - Sagara's key-shaped DIY Organic Pool in Cornwall. Puddling clay was used to create a big plug at the bottom. There is pond liner at the sides and the edges
3 Ways to Make Ponds Without Plastic Liners (and Help Save the World) — Steemit
The Best Koi Pond Liner Materials, And The Worst
HOW TO BUILD ALL NATURAL POND WITHOUT LINER |LOW COST+MAINTENANCE |BIG BACK YARD WATER LAKE HABITAT - YouTube