Cut cucumber into chunks. Add chunks to a medium sauce pan and add sugar and water. Place over medium heat and stir until sugar is dissolved. Remove from heat.
Add cucumber to blender and blend until pureed. Place in fridge to steep for 1 hour. When syrup is steeped, strain out cucumber pulp so that all that remains is the cucumber syrup. Add syrup to a medium pitcher.
Place strawberries in a blender, cover, and blend until smooth. Strain strawberries through mesh strainer to remove excess pulp and seeds. Add to the pitcher with the cucumber syrup. Add lime juice and water. Stir to combine. Add cucumber slices and strawberry halves for garnish.
Fill serving cups halfway with ice. Pour limeade into glasses with a few pieces of strawberry and cucumber slices. Serve with a straw and enjoy!