## 5 Discussion and Conclusions  
The preservation and conservation of the historic site is directly related to the actions of urban mobility management, so in the case of visitor mobility, it is essential to have the right tools. Knowing which areas are under tourist pressure effectively contributes to tourism and city management and competitiveness, providing decision-makers with improved tools to design better, smarter, and sustainable strategies; also contributes to optimise tourists' experience, which should be, ultimately, the goal of a smart tourism destination [55]. The application of different tools during different years in the same period and in the same historical city allows us to conclude the following aspects:  
Firstly, that the GPS (in standalone device, used in 2013) provides more accurate results. However, the NFC technology (used in 2015) offers more results, in terms of declaration of visits, by providing value with delivery of information. Secondly, the survey (used in the 2012 period) requires a higher level of interaction or collaboration of the tourist and a lower incorporation or technological infrastructure. It was the only tool used that collected records of visits after they had taken place, which showed that many of the data collected were not accurate because it was based, first, on the willingness of the tourist to answer the questions in the questionnaire, and second, on the ability of the person to remember the times (exact or not) of the sites visited at the destination. Thirdly, the tourist card (used in 2011) allows by means of incentives to the tourists, to capture their data of profile and the exact registry of date and hour, in which it visited the different tourist sites of the city of Popayan. This type of results coincides with those obtained in later works [29; 30]. Compared to the other tools, the card requires greater interaction of the tourist, since it is the tourist who takes the decision to accept it and present it in each associated establishment. One of the advantages is that this type of card does not require more supporting technology, since being a plastic card with a serial number; it does not demand more technology to be registered in each of the establishments. Likewise, it presentsadvantages related to a greater cooperation between different agents and also the greater visit of less known resources, which facilitates the distribution of flows outside the historic centre of the cities. In general, the results allow us to confirm that in the case of historic cities with an influx of tourists it is important to assess the availability of technologies and the use they can make of them to analyse the flow of their visitors. In the case of cities with the capacity to incorporate technologies in the data collection tools, they will obtain captures of a greater number of data or greater precision; among the tools with these characteristics, the most convenient to obtain the best information on tourist movements will be those that require low participation or interaction of the tourist so that data capture is as transparent as possible. In this sense, for future studies it is important to consider tools that incorporate NFC technology, which, according to our study, is the one that produced the best results. Other previous studies [62; 102; 103; 104; 105; 106] also confirmed that the use of NFC offers other services related to information supply, mobile payment, mobile ticketing, device pairing, access authorization, management of loyalty, bonus and membership cards. More recent works such as [107] confirm that in the case of MICE events, the use of NFC technology with a mobile application allows the experience to be improved for both the user and the organizer. Also, the Near Field Communication (NFC) technology has been applied previously in airports [108] and hotels [109]. In the touristic-cultural field we also can find applications such as museums [108; 110] or in tourism destinations.