Go to Sumiyoshi Taisha Shrine. This shrine is one of the most famous in Japan and is considered to be the home of the guardian deity of sailors. The taiko bashi (literally "drum bridge") is one of the most notable aspects of the shrine. With its peaceful and serene atmosphere, it is very popular with tourists, especially on holidays like New Year's Day.
Visit the Umeda Sky Building. The majestic and awe-inspiring Umeda Sky Building is 170 meters high and provides visitors with some of the most stunning panoramic views from above Osaka. The observation is open-air style and ring-shaped, and showcases a 360-degree view of the city below. Be sure to also check out the building's "Sky Garden," which is literally just that--a garden high up in the sky.
Check out Amemura ("American Town"). This vibrant and lively shopping district recreates an American shopping feel, with its many American brand names and shops, but the end result is very distinctly Japanese. The vibe is wonderful nonetheless. There are hundreds of hip boutiques, restaurants, cafes, clubs and bars.
Spend some time at the Osaka Castle Museum. This museum is located within the Osaka Castle and has a diverse collection of items from the Paleolithic age to the "Edo" Period. The central focus of this museum is Osaka's culture and history and there are many exhibitions devoted to these topics. Be sure to check out the nishiki-e (color prints) here.
Go to the Osaka Aquarium. One of the main exhibitions at the Osaka Aquarium revolves around the amazing Pacific "Ring of Fire." There are fourteen exhibits here focusing on the volcanic perimeter surrounding the Pacific. Over 380 species of aquatic life are on display at this aquarium. Be sure to check out the "vegetarian" whale shark exhibit here as well.