Gulladoo Lough is located near Carrigallen in County Leitrim, along the border between Leitrim and Cavan, and forms part of the greater River Erne system. The lake exists in two connected sections — Upper and Lower Gulladoo — separated by a bridge and amenity area managed by Leitrim County Council. The surrounding landscape consists of rolling drumlins and native trees typical of the Irish midlands drumlin belt.

The two sections are connected by a channel running under a bridge at the amenity area between them. Paddlers considering passage between the upper and lower lakes should be aware that this manoeuvre requires extreme caution and is only possible depending on water levels. A boat can be launched from the western shore of the upper lake via a gravel roadway extending approximately 200 metres, with car parking available at that point, again subject to water levels. On the lower lake, there is a launch point at the northern shore where the river exits, and this location also includes a facility for wheelchair users.

The lake connects downstream via the Cullies River to a chain of satellite loughs — Beaghamore, Tully, and Gortermone — located approximately 500 metres southwest of Gulladoo. These are linked by the Cullies river system, and access between them by water is possible depending on water levels. Cullies Lake lies downstream and northeast of Gulladoo, with bank access on its southern shoreline.

The water supports populations of pike, bream, roach, hybrids, tench, and perch, which indicates a productive, well-vegetated lake environment. The banks are described as comfortable in places, and there is a jetty near the outflow into the Cullies River on the lower lake. The area around the lake is suitable for birdwatching and general nature observation given the surrounding vegetation and relatively undisturbed shoreline in parts.

Access to the site from Carrigallen is straightforward: from the main street, turn toward Arvagh and after approximately 1.7 miles turn left following signs for the Gulladoo amenity. The lower lake is accessible from the roadside, and the upper lake is reached by continuing along and taking the first right past the village to the car park.