In a small bowl, whisk together the freshly squeezed lime juice and zest from two limes with ¼ cup of honey until smooth and glossy.

Preheat your grill to high heat, around 400°F (200°C). Cut the watermelon into 1-inch thick triangles.

Brush the lime mixture onto both sides of the watermelon triangles. Grill each piece for 2 to 3 minutes per side until caramelized.

Remove the grilled watermelon from the grill, sprinkle with cilantro, and drizzle with remaining lime mixture before serving.