In a small saucepan, combine cherries, water, and sugar.
Bring to a simmer over medium heat, stirring occasionally.
Simmer for about 10–15 minutes, until the cherries soften and begin to break down.
(Optional) Add lemon juice or zest for extra zing.
Remove from heat and let cool for 10 minutes.
Strain through a fine mesh strainer, pressing down gently on the cherries to extract maximum flavor.
Let the syrup cool completely, then transfer to a sealed jar or bottle.
Store in the fridge for up to 1 week.