"This is an extremely popular summertime dish in Bulgaria. It serves as a replacement for salad or appetizers. It tastes similar to tzatziki, so it's a very bright-flavored, cooling, and refreshing dish!"
Place cucumbers in a large bowl. Whisk yogurt in a separate bowl using a fork until yogurt is smooth and liquefied; pour over cucumbers. Add dill, garlic, oil, and salt to cucumber mixture; toss to coat. Stir in enough water to reach desired consistency. Refrigerate until chilled, at least 30 minutes.
Ladle soup into serving bowls; add about 2 ice cubes to each bowl.