If you have more time, explore Osnabrück's historic old town or visit Natura Artis Magistra, the oldest zoo in the Netherlands, and Van Gogh Museum in Amsterdam. If you want to save money, you can walk or bike around Amsterdam instead of taking a canal cruise. Alternatively, visit other free museums in Amsterdam like the Stedelijk Museum and the Museum Het Rembrandthuis. Remember to book tickets in advance for popular tourist attractions to avoid long lines.