Possible itinerary 

 BERLIN BY BIKE

 3-day tour:

sample itinerary for a 3-day bike tour in Berlin with two bikes and a guide:

Day 1:

• Meet your guide at your hotel and pick up your rental bikes
• Visit the iconic Brandenburg Gate and take a ride through the Tiergarten park
• Stop at the Victory Column for panoramic views of the city
• Ride to the Reichstag building for a guided tour of the German parliament
• Have lunch at a local café
• Ride to the Berlin Wall Memorial and learn about the history of the Cold War and Berlin Wall
• Return to your hotel for the night

Day 2:

• Meet your guide at your hotel
• Visit the Holocaust Memorial and learn about the atrocities committed during World War II
• Ride to Checkpoint Charlie and the Museum Haus am Checkpoint Charlie to learn about the history of the Cold War
• Stop at a local café for a break and lunch
• Visit the Pergamon Museum to see the impressive collection of antiquities
• Ride to the Friedrichshain neighborhood for a street art tour
• Return to your hotel for the night

Day 3:

• Meet your guide at your hotel
• Visit the Charlottenburg Palace, the largest palace in Berlin, for a guided tour
• Ride to the Berliner Fernsehturm for panoramic views of the city
• Stop at a local beer garden for lunch
• Ride to the trendy Kreuzberg neighborhood for a food tour and beer tasting
• Have a farewell dinner at a local restaurant
• Return to your hotel for the night

Note: This itinerary is just a sample and can be customized according to your preferences and interests. Your guide can suggest additional routes, landmarks, and places to eat, and can adjust the itinerary to your fitness level. Don't forget to bring comfortable clothes, sunscreen, and a helmet!