Here are a few interesting things to do in Istanbul. 

Planning to visit more than one museum?  Order a Muze Pass in advance and have it delivered to your hotel (72 Turkish Lire).  This gives you 3 days for the museums and you avoid the lines and walk through.  Saves you time.  Check the museums schedule before you travel - most are closed on Monday except for Topkapi,

1- For first timers, you may want to be close to the old city at Sultanahmet which is good for major historical sites, like the Blue Mosque (Sultanahmet Mosque in Turkish), St Sophia (Ayasofya) and the Topkapi Palace. 

2- Istanbul is famous for its mosques and you can visit them outside service times (avoid Fridays). Blue Mosque is magnificent! If you are going to visit one, this should be it! Give smaller and less famous mosques a chance, some of which are often more charming. Yeni Cami in Eminonu is nice.

3- St Sophia (Ayasofya) is worth a visit. It underwent a major restoration for decades and the roof is now fully visible.

4- If you want to visit Topkapi Palace, the Harem is quite nice. The nearby Aya Irini is a church which has been turned into a concert venue. Amazing atmosphere for a classical performance if you can book in advance.

5- Yerebatan Sarnici (the Basilica Cistern) is an amazing underground water cistern near the Palace. If you want to escape the chaos, this place is like an oasis of calm. Look for the upside down Medusa head!

6- If you are experiencing a dull drizzly day, you could go for a Hamam (Turkish Bath) experience. Go for the DIY option but if you are feeling adventurous, you can try a massage. A word of warning, the massage can be painful. Cemberlitas Hamami in Cemberlitas near the Grand Bazaar is beautiful and offers a traditional choice with several hundred years history. 

7- The Grand Bazaar (Kapalicarsi) is an interesting place to see, it is a labyrinth of old shops. Great to see but don't buy anything, it is a rip off! The Spice Bazaar (Misir Carsisi) is nearby which is full of character, colour and its amazing spicy scent.

8- Walking in this neighbourhood is an experience in itself.

9- Another interesting neighbourhood to visit is Beyoglu. From Sultanahmet, you need to cross over the Galata Bridge (this is NOT one of the suspension bridges!) which takes you over the Golden Horn. Beyoglu, also known as Pera was the upmarket glitzy part of Constantinople and is now full of nice cafes and restaurants.

10- Galata Tower is a small tower in Galata (as you climb up to Beyoglu) and the view from the top gives you Asia and Europe. 

11- There is the century-old funicular underground train that takes you from the bottom to the top of Beyoglu. When you get off at the top, you are at the end of Istiklal Caddesi with the old tram and lovely cafes and shops.

12- Try the old tram on Istiklal Caddesi, which goes through Beyoglu starting from Tunel to Taksim (which is Istanbul's Leicester Sq, vile!) You go past the main Catholic Church and Lycee de Galatasaray, which is the Turkish Eton. 

13- You can spend night after night on Istiklal Caddesi in Beyoglu. Nevizadeh is just behind the main street off Beyoglu (Istiklal Caddesi). Good for ouzo (called 'raki' here), beer and Turkish food. The alternative is the Cicek Pasaji on Istiklal Caddesi.

14- There is a wonderful veggie restaurant called Zencefil (pronounced Zenjephil) off Istiklal Caddesi. 

15- Robert's is very atmospheric in an old Constantinople style for a cup of medium Turkish coffee (again on Istiklal Caddesi). 

16- If you want to have a special dinner, try 360. It is in Misir Apartment on Istiklal Caddesi. The food is good, but quite pricey but the view from the top is worth everything. Also has a bar if you don't want to eat.

17- Try the 'Medrese' which is the old university next to Istanbul Uni. Nice spot for a cup of tea and 'hubbly bubbly'!

18- You can have a boat trip along the Bosphorus. The scheduled public ferries are a good bargain, which are not as long as the boat trip, cheaper and you get to travel with the locals. You can get a ferry asia-bound from Eminonu to Kadikoy and then take one back europe-bound. Try to sit outside (on the sides of the boat) and take some dried bread with you. Traveling with the seagulls as you feed them is a magical experience. When you re coming back to the European side, you get the best views of the 'City of Istanbul' with Topkapi Palace, the Blue Mosque, St Sophia and the Galata Tower. You will also go past the Maiden Tower (Kiz Kulesi). Don't be put off by the rain if it is wet. 

19- There are also tourist boats from Eminonu and Kadikoy. These last a couple of hours and take you through the Bosphorus towards the Black Sea end. Good opportunity to see the old and the new and some of the most expensive properties in the city. 

20- Getting around on public transport can be tricky. Avoid the buses, very confusing and busy. Taxis are good value but you get stuck in traffic. If the metro or the modern tram takes you anywhere, go for it. Walking is often the best option.

21- The easiest way from the airport is to take a taxi, they are reasonably priced and all have meters. Or take the Metro to the most central station and get a cab from there.  Be careful of the "Airport Taxis" that have kiosks when you exist the baggage claim.  You think they are taxis but if you take them, they are literally twice the cost of a regular yellow cab.

22- Istanbul is a massive city with 15 million population so you need to be streetwise. It is relatively safe (much safer than London) but beware of pick-pockets especially in busy areas. Shop keepers can be keen, especially in places like the Grand Bazaar but with good humour. 

23- Turkish people like talking (to strangers) and people are less reserved and more playful. 

24- Istanbul Modern and Santral Istanbul are two modern museums depending on what they currently have on.

25- If you see a newsagent, look for a Time Out, especially the one published in English. There are often interesting exhibitions and gigs.

26 - Shopping at the Spice Market or Grand Bazaar - Bargain on the price!  offer 1/2 or 2/3 of the price and they will meet you halfway.  That is what they are expecting. 

Sit back and enjoy this amazing city with an open mind.