Planning a tour for visitors with a stopover in Nur-Sultan is an exciting task! Let’s break down the itinerary step by step.

First, we need to figure out how to get from the airport to the city centre. The most convenient options are:

• Taxi: Taxis are readily available at the airport and can take you directly to the city centre in about 30-40 minutes, depending on traffic.
• Public Transport: There is also a bus service that connects the airport to the city centre. This option is cheaper but may take longer, around 1 hour.

Once we arrive in the city centre, here’s what we can see:

1. Bayterek Tower: Our first stop will be the iconic Bayterek Tower. It’s a symbol of the city and offers a great view from the top. We will spend about 30 minutes here.
2. Palace of Peace and Reconciliation: Next, we will visit this stunning architectural marvel. It represents the harmony of different cultures and will take us about 30 minutes to explore.
3. Hazret Sultan Mosque: After that, we will head to the Hazret Sultan Mosque, one of the largest mosques in Central Asia. We’ll spend around 30 minutes here to appreciate its beauty.
4. Independence Square: Finally, we will stroll through Independence Square, where we can take some pictures and enjoy the surroundings. This will take about 20 minutes.

For lunch, we can stop at a local restaurant to experience some traditional Kazakh cuisine. I recommend a restaurant called "Zheruyik," which is known for its delicious dishes. We can plan to have lunch from 12:30 p.m. to 1:30 p.m. This gives us enough time to enjoy our meal without feeling rushed.

To ensure that we arrive back at the airport by 3:30 p.m., we should plan to leave the city centre by 2:30 p.m. This allows us an hour to get back to the airport, accounting for any potential traffic delays.

In summary, our itinerary will look like this:

• Arrive at the airport: 9:00 a.m.
• Travel to city centre: 9:30 a.m. - 10:10 a.m.
• Visit Bayterek Tower: 10:10 a.m. - 10:40 a.m.
• Visit Palace of Peace: 10:50 a.m. - 11:20 a.m.
• Visit Hazret Sultan Mosque: 11:30 a.m. - 12:00 p.m.
• Visit Independence Square: 12:10 p.m. - 12:30 p.m.
• Lunch at Zheruyik: 12:30 p.m. - 1:30 p.m.
• Leave for the airport: 2:30 p.m.
• Arrive at the airport: 3:30 p.m.

This plan allows for a wonderful and efficient tour of Nur-Sultan while ensuring that we make it back to the airport on time!