**3. The Challenge of the SDGs and the Implementation of Indicators at the Local Level**

The literature on indicators in general, and the literature on indicators in urban contexts shows that sustainability indicators are used to monitor change in society and show progress towards a given goal or objective, based on observable or measurable markers [31–34]. Indeed, an indicator can be defined as an observable characteristic that is supposed to represent a generally unobservable state or trend at a given time [35,36].

In particular, the SDG indicators pose great challenges regarding their implementation at the local level [37]. Although they recognize the role of cities in sustainable development, the 2030 Agenda was agreed and signed by national governments. So, the territorialized implementation of its targets and indicators requires a process of adaptation and/or localization [38].

The challenges mentioned specifically refer to the availability and access of reliable, spatial, specific, standardized, open, comparable, measurable, and observable data at the urban level [38–44]. This is often framed by a lack of solid institutions dedicated to data collection at the city scale [44]. Therefore, the challenges of accessing the data located at the local level must include the selection of a set of limited indicators that manage to reflect aspects necessary to evaluate the sustainability of a city [42]. In addition, the data must necessarily be simplified for monitoring so that it can be replicated in several cities [43], which would allow cities to be compared based on the relevant evaluations.

In this context, SUA appears to be a very useful tool in this field since it transfers the urban goals of the SDGs of the 2030 Agenda, especially SDG 11, to the reality of towns and cities. The 17 SDGs are:


The SUA even has its own objectives and indicators that are aligned with the goals of the 2030 Agenda, making it a practical tool for achieving the SDGs at the local level. As shown in Table 2, the SUA links each of its 10 Specific Objectives to the SDGs [45].

**Table 2.** Relationship of each Specific Objective of the SUA with the SDGs.


Using data from an official government source such as the SUA and its consequent reflection of urban realities is what this research carries out. As increasingly more guidance is available on the localization of the SDGs [42,46,47] and research that highlights the challenges in implementing the SDGs at the local level, it is vital and necessary to acquire experiences to be able to work with the SDGs in practice and make them a tool to achieve sustainable development [42].

This article reflects the situations of the evaluated cities in achieving sustainable development and the Specific Objectives of the SUA, thus the SDGs, are identified. Based on the results obtained, cities have the capacity to influence local and regional conditions through policy intervention [48] in planning and decision-making, in creating awareness, in the encouragement of behavior, in the promotion of public participation [44], and in alignment with the SDGs. In any case, the realities of urban sustainability in a particular region that needs to become strong, unite, and work together for current and future problems and challenges are discovered and made visible.

#### **4. Materials and Methods**

#### *4.1. Data Selection*

Given the need to count and select quantitative, locally applicable, statistically comparable indicators from official sources, the SUA Descriptive Data was selected. They are related to the ten Specific Objectives that the SUA has.

Access to the SUA Database is free on the Spanish Urban Agenda website [3]. The Database has a table that collects information available from all the Spanish municipalities, with more than 50 descriptive data on the SUA, and another table in which the data corresponding to the first quartile, the median value, and the third quartile are offered according to the cluster by population size: municipalities with more than 100,000 people, municipalities with between 50,000 and 100,000, between 20,000 and 50,000, between 5000 and 20,000 people, and municipalities with less than 5000 people. This database of over 200,000 data allows not only for data related to a one municipality to be obtained but also to make a comparison with municipalities with similar characteristics, such as the population.

Regarding the sources of information used to calculate the SUA Descriptive Database, the most recent data possible was used. These data can be requested from the Ministry of Transport, Mobility and Urban Agenda of the Government of Spain, and obtaining them facilitates an approximation to the current situation of each Spanish cities, configuring itself as a useful tool for decision-making and the establishment of specific goals to be achieved.

For the realization of this article, values were extracted (in July 2021) from the SUA Database and those that correspond to the cities of Castilla y León related to The French Way of Saint James were selected: Astorga, Cacabelos, León, Ponferrada, and Valverde de la Virgen (province of León) and the city of Burgos (province of Burgos). Of the 72 descriptive data made possible by the SUA Database, a total of 49 were considered for the analysis (Table 3). The rest of data was not available or did not indicate quantitative data to be analyzed, as is the case, for example, of the indicators D.38 and D.39 ("Date of the current urban planning figure in the municipality" and "Agenda Planning, Strategic Planning and Smart Cities", respectively).

Each of the SUA databases used, with its definition, relevance, and calculation methodology according to the SUA, are described in the document "Descriptive Data of the Spanish Urban Agenda" available on the SUA's web platform.
