Don´t you know what to do upon arrival in Cusco? Well, in that case, I hope you find these suggestions useful:

1. Take it Easy!
This is the most recommended piece of advice (and perhaps the wisest): take a nap in your hotel after drinking a hot mate de coca. You should bear in mind that Cusco is about 3,300 meters which is over 10,000 feet, so if you are not accustomed to this high altitude there is always the risk to suffer altitude sickness or soroche. If going out anyway, just walk slowly especially on steep slopes and eat lightly.

This may sound boring and in fact it is, but it is better than risking your whole journey. However, you can make short walks around the city to visit the places I describe below.

"first day in Cusco"
Inca walls near the main square

2. Centro de Interpretacion del Santuario Historico de Machu Picchu y del Parque Nacional del Manu:
In this Interpretation Centre you can get a glance of Machu Picchu as well as the Natural Park of Manu. It is located on Avenida el Sol 103 at the end of the corridor, and it opens monday to friday from 8:30 am to 1pm and then from 2pm to 4:30pm. You can also go on Saturdays from 10am to 12pm if you do not care watching them cleaning the room.

The entrance is free and I consider it a great choice to start your visit in Cusco.

3. Take Advantage of your Boleto Turistico:
The Boleto Turistico (BTG) is your ticket to 16 attractions out of which 6 are in the very city. Thus, there are four museums, one lookout, and one dance centre (see the fourth suggestion).

I would recommend that you visit three museums in this order: Museo de Sitio Qoricancha (underground), Museo de Arte Popular, and Museo Histórico Regional or Garcilaso´s House. You would not take more than 20 minutes for each one as they are all very small, and all in all they open everyday from 8am to 5:45pm (check your ticket anyway).

Also check all the museums in Cusco.

4. Enjoy Local and Peruvian Dances:
The Centro Qosqo de Arte Nativo features regional and Peruvian dances daily from 6:30pm to 8pm. It is located at the fifth block of Avenida el Sol almost in front of the Temple of the Sun or Qoricancha. Entrance is included in the Boleto Turistico though you can also pay for this only place.

5. Inka Museum:
This museum is open from Monday to Friday from 8am to 5pm, Saturdays and holidays from 9am to 4pm, and Sundays is closed. It is located on Cuesta del Almirante 103 just one block off the main square. Entrance  costs 10 soles.

6. Museo de Arte Precolombino or MAP:
This museum as well as the Inca Museum are a must if you want to know the development of the arts in the Andes. This museum is located at the Plaza Nazarenas, two blocks from the main square. It opens daily even holidays, and the best of all is its ample schedule from 9am to 10pm, so you can visit this place after dinner. Entrance is 20 soles and students pay 10 soles.

"first day in Cusco"
Museo de Arte Precolombino

7. Handicrafts, Fairs and Parade:
You can check out prices of handicrafts and souvenirs at three fairs which open daily. The most important one is at the end of Avenida el Sol.
In the San Blas main square there is also an open air handicraft fair on Saturdays.
If you want to take a look what local people eat you can go to the Plaza San Francisco where an open-air food fair is held every sunday.
Also on Sundays from 10 or 11 am, there is a parade at the main square which features local dances and customs.

8. Go to Sacsayhuaman:
If you do not have any problem with altitude, you may want to sightseeing this nearest Inca site which is indeed impressive. Even better if you take advantage of your time and visit the three other nearby sites such as Qenqo, Pukapukara and Tambomachay. You can do this by taking a taxi, bus or hiking. Ask directions at the front desk of your hotel but eventually the route is just easy to follow.

Related Topic:
Sacsayhuamán: All You shoud know

9. City Tour:
If you prefer to go with a travel agency, you can take the City Tour which includes the four sites mentioned above and the entrance to the Cathedral and the Site Museum of Qoricancha (undergrounds). This tour begins at about midday, and you come back to Cusco at about 6 or 7pm. The average price is US$15 which includes bus and guide but not entrance which you can buy at the first point of the tour.

10. Take a Ride around the city:
If you just want to take it easy on your first day in Cusco, you can take a look of the city and its attractions on a bus or trolley. You would find the “trolley” or tranvia de Cusco as well as the red and yellow double deck buses at the main square everyday. The trip takes about 1 hour 30 minutes in different hours starting around 8 or 9am.

Could you add any other suggestions for the first day in Cusco?

"first day in Cusco"
Balconies at the San Francisco square in Cusco

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