Found this in a cookbook- what a great way to enjoy rhubarb!
Combine in a pot and cover with water, bring to a boil and simmer 3-4 minutes:
10 stalks rhubarb, sliced into chunks
2 cinnamon sticks
Take off heat, strain.
Whisk in honey or agave syrup to desired sweetness.
Pour into glasses with ice and sparkling water. Garnish with mint leaves or sliced strawberries.