## 1 Introduction  
Today, the development of new products is receiving more and more attention, especially regarding design aspects that are closely related to \"design for all\", \"user-centered design\", and \"eco-design\" methods [1; 2; 3; 4; 5; 6; 7]. In fact, several products are designed from scratch or redesigned to consider user's needs, inclusion, and general environmental sustainability aspects. In the field of medical device design as well as assistive technologies for people with disabilities, it is possible to observe a growing interest in the development of more functional and sustainable devices to be used in the context of Accessible Tourism (AT) initiatives. In this context, AT means all services and products used for tourism activities implemented with consideration of the needs of the full range of consumers, including disabled and elderly people. Indeed, AT requires the removal of attitudinal and institutional barriers in society and therefore includes accessibility to the physical environment, transport, information and communications, and other facilities and services [8]. The current situation sees a constant aging of populations, especially European ones, which is tackled by the continuous updating of the legislative framework, but also by the growing evolution of the available design and production techniques. This contributes to making AT increasingly popular and thus increasing the demand for further types of tourism activities and services [9; 10]. The presented project fits into this context of growing interest in AT, and aims to describe the design, manufacturing, and testing of a special wheelchair for people with impaired mobility to use in AT activities, developed by the University of Brescia and named the \"Golem project\" [11]. This peculiar name refers to the local dialect version of \"Mount Guglielmo\" (Brescia, Italy), the highest mountain (1957 m) on the University premises, and a very loved trekking destination for locals. The Golem project considers the AT initiatives in mountain areas and specifically the activity of accompanying people with every major type of mobility issue on mountain trails, using dedicated wheelchairs. This should be implemented while considering an environmentally friendly production and use of the device. The literature analysis, combined with the market analysis described in previous work [11] highlighted the presence of several available technical solutions, as briefly reported in the following. Solutions can be divided into three main categories: self-propelled wheelchairs designed for developing countries; self-propelled off-road/all-terrain wheelchairs; and a new category of devices classified as trekking wheelchairs--ISO code 30.09.39 (according to ISO 9999:2016) [12; 13; 14; 15; 16; 17]. The latter is the most promising and interesting for the development of devices suitable for AT initiatives. This class of products consists of a specific type of human powered trekking wheelchair similar to a sedan chair equipped with a wheel, conducted by at least two carriers managing the impaired boarded guest over rough terrain. Currently, there are only a few commercially available solutions of these trekking wheelchairs. The most well known are: Joelette(r) and TrailRider(r), presented in Figure 1[16; 17]. They are characterized by a single-wheel configuration with an ergonomic cushioned seat, equipped with safety belts. Each one has a back handle and a couple of front arms allowing the carriers to handle the vehicle properly and its precious load on challenging terrains. The use of these aids is mainly performed by charities organizing excursions along mountain trails for disabled guests; such activity has highlighted some objective limitations of these devices at the same time suggesting the direction for improvements. This paper describes the preliminary testing phase of the prototype of our trekking wheelchair, reporting the description of qualitative tests, aimed at drivability and balance validation of this first \"proof of concept\" prototype.