Mom's Italian Potato Salad

Place potatoes in a large saucepan, cover with water, and bring to a boil over high heat. Reduce the heat to medium-low, and simmer until the potatoes are tender, about 15 minutes. Drain and cool, then cut into 1-inch cubes. Combine the potatoes, cucumber, celery, onion, and olives in a large bowl. Whisk together the olive oil, red wine vinegar, and garlic powder in a small bowl. Pour the dressing over the potatoes and vegetables; mix well. Season with salt and pepper, then chill. Stir the potato salad again before serving.