1. In a large bowl, combine cucumbers, tomatoes, onion, parsley, and olives.
2. In a small bowl, mix olive oil, lemon juice, and oregano.
3. Break feta cheese into about 1/2-inch chunks and add to cucumber mixture. Add dressing and mix gently, adding salt and pepper to taste.
Note: Nutritional analysis is per serving.
Notes: You can prepare through step 2 up to 4 hours ahead; cover and chill vegetables and dressing separately. Just before serving, pour cucumber mixture into a colander to drain off any liquid, then return to bowl and mix with feta cheese and dressing.