Read the passage below.
When we first cleared the vacant lot on Elm Street, it was nothing but broken glass and stubborn weeds. The soil was compacted, depleted of nutrients, and seemingly hostile to any form of plant life. To most passersby, the site was merely an eyesore, a neglected corner of an urban landscape. Yet, within three seasons, a dedicated group of volunteers transformed the barren dirt into a vibrant community garden. Now, tall sunflowers line the wooden fence, and rows of organic tomatoes and squash flourish in the midsummer sun. The garden has truly become the heart of the neighborhood, pumping energy and life into the once-quiet streets. Neighbors who had previously lived in isolation now gather daily, trading family recipes and sharing gardening tips over the hand-built compost bins. It is more than just a space to grow food; it is a vital organ that keeps our local community connected and active, transforming strangers into close friends and restoring a sense of shared pride in our surroundings.
Based on the passage, what is the best word to complete the description of the metaphorical phrase 'the heart of the neighborhood'?