OOTY
5 km from Avalanche Lake and usually visited on the same trip. Pair it with Avalanche only if the day's access rules and road conditions allow - don't plan it as a separate outing.
Emerald Lake and Avalanche Lake are technically one continuous reservoir divided by a small bridge at Surukipalayam, together forming part of the Tamil Nadu Electricity Board's Kundah Hydro Power Project. The surrounding Emerald settlement grew up around tea estates, vegetable farms, and an electricity board housing colony established as the hydroelectric infrastructure was built out in the Nilgiris through the 20th century.
