The Calming Cove is another area in Monster Harvest. It can be found to the west if you leave from the center of town. Just like the Glowing Glade, you will need 1,500 money to open the way to the Calming Cove.
Walking up to the rock obstructing the way will prompt you to pay and unlock it. Upon entering the Cove you will start a cutscene where Vex thanks you for opening up the way and gives you a fishing rod. Vex will also offer to upgrade your fishing rod if you bring the correct materials.
As fishing offers a new way to earn money, it is better to unlock the Calming Cove before the Glowing Glade. The Calming Cove also offers another area where you can forage for wild food and flowers. Selling these each day will allow you to keep a small but steady income. You can also harvest wood and stone here.
Unlocking Calming Cove also adds a new area to fish in and you can only catch certain fish in its salty waters. As the town, your farm, and the Glowing Glade feature freshwater, the Cove is essential if you want to catch all of the different fish types.
For more information on Monster Harvest, check out How to sell items in Monster Harvest and How to get titanium in Monster Harvest? on Pro Game Guides.